Effect of deletion of gene cluster involved in synthesis of Enterobacterial common antigen on virulence and immunogenicity of live attenuated Salmonella vaccine when delivering heterologous Streptococcus pneumoniae antigen PspA

Bibliographic Details
Title: Effect of deletion of gene cluster involved in synthesis of Enterobacterial common antigen on virulence and immunogenicity of live attenuated Salmonella vaccine when delivering heterologous Streptococcus pneumoniae antigen PspA
Authors: Qing Liu, Xuegang Shen, Xiaoping Bian, Qingke Kong
Source: BMC Microbiology, Vol 20, Iss 1, Pp 1-12 (2020)
Publisher Information: BMC, 2020.
Publication Year: 2020
Collection: LCC:Microbiology
Subject Terms: ECA, Salmonella Typhimurium, Virulence, Vaccine vector, Th2 immunity, Microbiology, QR1-502
More Details: Abstract Background Enterobacterial common antigen (ECA) is a family-specific surface antigen shared by all members of the Enterobacteriaceae family. Previous studies showed that the loss of ECA results in Salmonella attenuation, indicating its usefulness as a vaccine candidate for Salmonella infection, but no studies have shown whether the mutation resulting from the deletion of the ECA operon in conjunction with other mutations could be used as an antigen vehicle for heterologous protein antigen delivery. Results In this study, we introduced a nonpolar, defined ECA operon deletion into wild-type S. Typhimurium χ3761 and an attenuated vaccine strain χ9241, obtaining two isogenic ECA operon mutants, namely, χ12357 and χ12358, respectively. A number of in vitro and in vivo properties of the mutants were analyzed. We found that the loss of ECA did not affect the growth, lipopolysaccharide (LPS) production and motility of S. Typhimurium wild type strain χ3761 and its attenuated vaccine strain χ9241 but significantly affected the virulence when administered orally to BALB/c mice. Furthermore, the effects of the ECA mutation on the immunogenicity of a recombinant S. Typhimurium vaccine strain χ9241 when delivering the pneumococcal antigen PspA were determined. The result showed that the total anti-PspA IgG level of χ12358 (pYA4088) was slightly lower than that of χ9241 (pYA4088), but the protection rate was not compromised. Conclusions ECA affects virulence and benefits the Th2 immunity of Salmonella Typhimurium, therefore, it is feasible to use a reversible ECA mutant mode to design future Salmonella vaccine strains for heterologous protective antigens.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1471-2180
Relation: http://link.springer.com/article/10.1186/s12866-020-01837-0; https://doaj.org/toc/1471-2180
DOI: 10.1186/s12866-020-01837-0
Access URL: https://doaj.org/article/e9e29363dcfb4b49a13a6b4bc8fe8b35
Accession Number: edsdoj.9e29363dcfb4b49a13a6b4bc8fe8b35
Database: Directory of Open Access Journals
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More Details
ISSN:14712180
DOI:10.1186/s12866-020-01837-0
Published in:BMC Microbiology
Language:English